Relief-Well Plan Was Used in Worst Blowout Ever, Took 9 Months

A boat works to collect oil that has leaked from the Deepwater Horizon wellhead in the Gulf of Mexico on April 28, 2010 near New Orleans, Louisiana. Photographer: Chris Graythen/Getty Images

April 30 (Bloomberg) -- The worst blowout on record took
about nine months to cap using two relief wells, the same
technique BP Plc has said it will deploy to stem gushing crude
from the Macondo well in the Gulf of Mexico.

In 1979, Ixtoc-1, an exploratory well owned by Petroleos
Mexicanos in 150 feet of water, blew out 600 miles (966
kilometers) south of Texas in Mexico’s Bay of Campeche and
spilled an estimated 3.3 million barrels into the Gulf,
according to the Royal Swedish Academy of Sciences and the
American Petroleum Institute.

Oil from the BP well, which blew out April 20, is escaping
at a rate of about 5,000 barrels a day, five times faster than
previously estimated, according to the U.S. Coast Guard. The
Deepwater Horizon rig exploded and sank last week, killing 11
crew members, while drilling in 5,000 feet of water.

“There is likely going to be more oil coming ashore than
Ixtoc,” Paul Boehm, who was an oceanography contractor with the
National Oceanic and Atmospheric Administration at the time of
the 1979 spill, said today in a phone interview. “This spill
has challenges that nobody has faced before.”

The oil and natural gas blowing out of Ixtoc-1 ignited,
causing the platform to catch fire, according to NOAA. The
platform collapsed into the wellhead area, hindering immediate
attempts to control the blowout, which spilled 10,000 to 30,000
barrels of oil a day.

Relief Wells

Two wells were drilled to relieve pressure from Ixtoc-1 so
that it could be capped, according to NOAA. BP, based in London,
said today that its relief-well operation should begin tomorrow.

The differences between the two spills are more worrisome
than the similarities, said Boehm, who is now principal
scientist at Exponent Inc., a scientific and engineering company
in Boston.

The oil from Ixtoc-1 took two months to be transported,
which changed the composition of the crude and made it less
toxic, Boehm said. The length of time allowed U.S. responders to
prepare for the spill. The composition of the oil from the BP
well will be different, Boehm said.

“The oil has been out there eight days now,” he said.
“The more it weathers, the less toxic it is.”

Oily Beaches

About 71,500 barrels of oil from Ixtoc-1 affected 162 miles
of U.S. beaches and more than 10,000 cubic yards of oiled
material were removed, according to the Industry Technical
Advisory Committee, a U.K.-based oil-spill organization of
technical experts. The U.S. Fish and Wildlife Service used
volunteers for handling oiled birds and beach patrols on South
Padre Island.

“This will be a lot worse,” said Miles Hays, a coastal
geologist with Research Planning Inc. in Columbia, South
Carolina, who studied the Ixtoc-1 spill.

The oil from the Ixtoc-1 spill hit the 90-miles of Texas
barrier islands, protecting the environmentally fragile marsh
lands from the spill, Hayes said in a phone interview.

“You want to keep the oil from getting past the barrier
islands,” Hayes said. “After Ixtoc, in Texas it wasn’t too
tough because we had only three inlets. Louisiana is a different
scenario.”